Wall mounted fuel burning space heater



'7 Sheets-Sheet l H- 9.2 Jrsamm TTORN EYJ March 24, 1953 A. w. LUNDsTRUM WALL MOUNTED F UEL BURNING SPACE HEATER Filed June 28, 1947 March 24, 1953 A. w. LUNDsTRUM WALL MOUNTED Fusi. BURNING SPACE HEATER 7 sheets-sheet 2 Filed June 28, 194'? @M1532 ----l-: l..---litxljodlllf@ mtu INVENTOR y I ALLAN w. LuNsrRuM March v24, 1953 A. w. LUNDSTRUM 2,632,435

WALL MOUNTED FUEL BURNING SPACE HEATER Filed June 2e, 1947 7 sheets-sheet a urk h 9 INVENTOR ALLAN W. LUNDSTRUM 2mg FM W' A ToRNEYs- March 24, 1953 A. w. LUNDSTRUM 2,632,435

wALL MOUNTED FUEL BURNING sPAcE HEATER Filed June 28, 1947 7 Sheets-Sheet 4 ALLAN W. LUNDSTRUM ATTORNEYS.

March 24, 19.53 A. w. LuNDs-rRuM WALL MOUNTED FUEL BURNING SPACE HEATER Filed June 28, 1947 '7 Sheets-Sheet 5 F i9 Il INVENTOR ALLAN W. LUNDSTRUM www? A. w. LUNDSTRUM WALL MOUNTED FUEL BURNING SPACE HEATER March Y24, 1953 7 Sheets-Sheet 6 Filed June 28, 1947 INVENTOR i@ WE* March 24, 1953 A. w; LU'NDsTRuM i A 2,532,435 WALL MOUNTED FUEL BURNING SPACE HEATER Filed June 28, 1947 7 Sheets-Sheet 7 il L51 INVENTOR ALLAN w. LuNDsrRuM ATTORNEY Patented Mar. 24, 1953 WALL MOUNTED FUEL BURNING SPACE HEATER Allan W. Lundstrum, Anderson, Ind.

Application June 28, 1947, Serial No. 757,776

17 claims.

This invention relates lto heating devices and relates more particularly to gas or liquid-fired heating Adevices. particularly adapted for domestic use as an auxiliary to or as lsubstitute for so-called central heating systems in the indi vidual space heating of separate rooms, enclosures, compartments and the like.

Objects and advantages of the invention will be set forth in part hereinafter and in part will be obvious herefrom, or may be learned -by practice with the invention, the same being realized and attained by means of the instrumentalities and combinations pointed out in the appended claims.` y Y The invention consists in the novel parts, constructions, arrangements, combinations and improvements herein shown and described.

The accompanying drawings, referred to herein and constituting a part hereof, illustrate one embodiment of the invention, vand together with the description, serve to explain the principles ofthe invention. Y

Objects of this invention are to provide la new and improvedvheating device which is particularly yadapted for wall installation and use in existing buildings,` vehicles or other structures to be heated, as a main or auxiliary space heating unit; which is of a conguration and arrangement such that its installation in such structures may be carried out speedily and with only minor alterations of the existing structure; which combines a high degree of thermal effici'ency and heating duty per unit of volume with extreme accessibility for inspection and servicing .and with substantial freedom from moving parts; which is adapted for operation on either gaseous or liquid fuels and is characterized by freedom from hot spots through the provision of a novel and improved' internally fired transfer unit offering uniform heat distribution and high heat radi-ating capacity; which is characterize'd further by a novel and improved venting system for so `directing and controlling the induction of air to and the eduction of gaseous products of combustion from the combustion chamber Vof' the heat transfer unit that for all practical purposes the combustion chamber is adapted'to be vented and may be vented directly f to 'the outside air without the usual lengthy pipes, ducts', chimneys and the like and without danger of blow-out of the flame, under substantially any and all atmospheric conditions to which the induction and eduction'ports ofthe heat transfer unit may be subject in use.

Another object of this invention isto Aprovide 2 a new and improved wall-vented space heating device adapted for operation on either gaseous or liquid fuels which may be installed in new or existing wall structures of greater or lesser relative thickness through the provision of a novel and improved venting system for the'combustion chamber adjustable to compensate for the different wall thicknesses encountered inV fashion by mass production technique from materials of low cost and in ample supply.

Of the drawings: Figureflv is a view in vertical section of a typical and illustrative embodiment of a space heating device in accordance with this invention,dthe view showing inside elevation the convector case which encloses the heat transformer unit.

showing the device as installed in an outside wall structure of a room and showing also a preferred form of exterior hood-baiie of the a'djustable vent system by which the combustion chamber of the heat transfer unit is vented through the wall structure to the outside air;

Figure 2 is a view in vertical section of the embodiment shown in Figure 1, the view being taken along a vertical plane passing' through the heat transfer unit and showing the manner in which the burner assembly is disposed at the bottom of the combustion chamber;

Figure 3 is a view in front elevation of the embodiment shown in Figure 1, showing the room cover-panel in full line, and showing, in dotted outline and assembled relationship rearwardly of the room panel, the heat transfer unit with its burner assembly, the convector case surrounding the heat transfer unit, and theroughin-box forV mounting the device in a wall structure;

Figure 4 is a View in elevation of the exterior hood-baflie of the vent system of the device of Figure 1 in installed position on an outside wall structure;

Figure 4a is a viewin section of the exterior 3 hood-bafiie, taken along the line 4-4 of Figure 4;

Figure 5 is a s-o-called exploded isometric view of certain of the major elem-ents of the device of Figure 1 wherein the elements, reading from left to right, are: the room panel, the heat transfer unit, the ccnvector case, and the roughin-box, the exterior hood-baffle being omitted in this instance;

Figure 6 is a view in section taken substantially along the line 6 6 of Figure 1 and showing the elements in their assembled relationship to each other and to a wall structure in :which the de.- vice is installed, the view omitting, however, the exterior hood-bae of the adjustable venting system, for clarity in showing;

Figure '7 is a view in front elevation yof the heat transfer unit of the device of Figure l, omitting the detachable burner assembly which is normally positioned in front of the combustion airinlet opening of the unit, as shown in Figure 2;

Figure 8y is a, view in side elevation of the heat transfer unit of Figure '7 showing the arrangement of. its exhaust gasr (upper) duct and its combustion air (lower) inlet duct;

Figure 9 is a View in rear elevation of the heat transfer unit of Figure '7, the YView vshowing further details of the form and arrangement of its lower, or air-inlet, duct and of its upper, or exhaust-eas; duct;

Figure l0 is a viewin elevation of the dorsal side of the fronthalf-section of the Vheat transfer unitof -Figure '7;

Figure 11 is a. view in elevation of the dorsal side of the backhalf-section of the heat transfer unit of Figure'7;

Figure Y12 is a fragmentary view in elevation with parts in section of a detail of the pilot light and igniter apparatus of the burner assembly shown in Figure3;

Figure 13 is a view in section taken along the-- Figure 14; is Aa view in top plan of the removable burner assembly shown in installedposition in Figure 1 and in Figure 2, the View vomi-tting the thermo-cgntrol-means and-igniter means; f or clarity;

Figure V15 is a view in front ,elevation of the. burner shown in Figure 14, the burner holder beingl shown in part in dottedoutline; and,

Figure 16 is a-view in section with parts broken away taken along the line iiit6 of Figure 14.

In general, and in accordance with thisr in vention, there is provided an internally firedA compact heating unit adapted for operation on a combustible fluid mixtureand intended for installation partly within and partly without a room, compartment, chamber, or other space that is to be heated. The heating unit, as embodied, comprises, in close-coupled adjustable and separable relation to each other, hollow heat transfer means whose interior forms` a combustion chamber and is provided with means for burning a combustible fluid mixture; and, novel external, baffle means for conducting combustion air to and` conducting products of combustion from theheat transfer means. The close-coupled adjustable. relationship of the Yheat transfer means and -the external baiiie means enables an installation in:- which the heat transfer means may be disposed at one side of a dividing wall structure and substantially wholly within the space to be heated' whereas the baffle means may be disposed on the other side of the wall structure substantially wholly .outside of the space. with duct elements 4 adjustably connecting the heat transfer means and baie means through the intervening wall structure of the room.

The heat transfer means as embodied is provided with heat absorbing and heat radiating fins on its inner and outer surfaces, respectively, these fins being of a size, configurati-on and arrangement to effect a high heat recovery from the burning fuel mixture and from the combustion 'products in their travel from bottom to top of the heat transfer means and to effect a maximum heat radiation, with a minimum of hot spots, to the` air stream flowing upwardly over the; outer finned surface. To this end also the heat transfer means is suitably internally baiiied tcprovide a turbulent and longer ow of the hot products of combustion within the heat transfer means, thereby to effect increased heat recovery prior to discharge of the products of combustion through the exhaust gas duct and associated baiiie means.

In accordance with this invention also, the heat transfer means as embodied is of cast construction and comprises front and rear half-sections of suitable configuration detachably sealingly connected to each other to provide a closed and sealed fire chamber except for the air inlet and exhaust gas openings. The lower portion of the front half -section is .preferably independently removable from the heat transfer means as a whole and carries, in readily separable association therewith, the novel fuel burning means of this invention.

Combustion air for the fuel burning means is supplied thereto through the external baffle means and an air inlet port or terminall located substantially at the bottom of the rear half section of the heat transfer means. This terminal is adjustably connected through suitable duct means with the external baie means so that the heat transfer means and the baffle means may be moved toward or away from each other to allow for differences in wall structure thickness in different installations.

Means areprovided in the fire chamber of the heat transfer means for co-action with the fuell burning means to cause the entering air stream for combustion to flow rapidly upwardly around the burner per se so as to form a relatively cool insulating uid stream between the burnerl proper and closely Vadjacent wallsV of the heat transfer member. In this Way', the formation of hot' spotsin the walls ofthe heat transfer member in the immediate proximity of the burner .v proper is greatly minimized and the possibility of structural failure due to excessive localized heating is substantially eliminated.

Fuel for ,combustion is 'supplied to the fuel burning means through suitable, temperaturecontroll'ed fuel supply means and novel means are provided in `accordance with this invention forY lcontrolling the primary airfuel ratio of the burner from the outside of the heat' transfer member and, at will. To this end also the heat transfer means may be lprovided with a small window of transparent heat resistant material permittingA Observation of the burner ,flame during operation.

The eductionV of the products of combustion from the re chamber is effected through an exhaust gas terminal or yopening situatedf at the baci; of the fireA chamber suiciently below the top that' the products of combustion, divided into separate streams bythe internal -baiile means, are 12a-used i0 :reverse their direiien .0i 110W '5 in seeking the exhaust port, thus providing a longer `flow path and promoting turbulence within the heat transfer means and a more efficient heat transfer tothe `heat radiating surfaces. Moreover, in thus locating the exhaust port` at some distance from the top of the heat transfer member and hence nearer to the air `intake opening.these openings are` caused to be located in substantially the same static or barometric pressure area. Such a. disposition is of the utmost importance to ensure that under practical conditions of operation, `wherein the inlet and `exhaust openings are both open-to the atmosphere, the effect of high wind velocities, gusts, downdrafts, and such disturbing atmospheric conditions will not be to Y cause sudden flame blow-out or smothering due to recirculationof products of combustion. In accordance with this invention, therefore, the products of combustion are discharged through the exhaust port into the external baffle meansr and thence to Suitable ductrneans connect` `ing the heat transfer means and the external the atmosphere.

baiiie means enable relative movement of these elements toward and away from each other to permit of accommodation tovarying wall thick.

nesses, just as in the case of the air lintake port. i

The external `baille means, as embodied, comprises a system of air-guiding and air-directing f barometric pressure will be maintained over the area between said ports regardless of the external wind velocity and direction. To these ends, the

system of air-guiding and directing vanes and surfaces `forms an air bypass chamber externally of the space `to be heated in close proximity to the intervening wallstructure and directly in back of the heat transfer means, Vthe chamber w having connections substantially at its opposite ends withl the air-inlet and exhaust gas ports of the combustion chamber. Openings are provided in the chamber wall structure substantially at the opposite ends of the air bypass chamber for .the admission of` fresh combustion air to thev chamber and for the discharge of products of combustion therefrom. These openings, which are sometimes hereinafter referred to for convenience as baffle openings, are so located` with reference to the air inlet` and exhaust gas ports of the combustion chamber and are of such configuration, that the desired unidirectional` ow .through the combustion chamber will be maintained at all times during operation, regardless of the direction and velocityof the wind striking the baffle openings. Thus,` the baiiie inletv opening is located directly opposite the air inlet port of the combustion chamber and certain of the air directing and guiding vanes and surfaces ofthe system above-noted are suitably arranged ,at the baffle inlet opening to funnel an approaching air stream into and through the yair bypass. chamber intoA the air inlet port of they'combustion chamber regardlessof the Avenlocity and direction of approach of the air stream. With the same object in view of maintaining this unidirectional flow through the combustion chamber, certain other air-directing and guiding vanes` and surfaces of the system are suitably arranged at the baffle outlet opening so as to shield the exhaust port of the combusv tion chamber against entry of air blowing directly at the exhaust port and so as to `utilize the kinetic energy of air blowing at said port from other directions, to increase the normally low pressure, drop through the combustion chamber by Venturi action at the baflie outlet opening.

In accordance with this invention also, means are provided for conducting air to be heated over the heat transfer means in a confined stream from bottom to top so that by thermal convection cool air from the space to be heated will continuously enter at the bottom, `be heated, and flow out at the top of the heating device. To this end, the heat transfer means is removably mounted in a shallow convector case, or pan, open at the front and closed at the back except for1 openings through which extend the intake and exhaust conduits of the unit. The case at its top and bottom is preferably smoothly faired from its front toward its back to effect a smooth air flow through the case and upwardly around the heat transfer means which latter is carried in amply spaced relation thereto for effecting this result. At its discharge end, the case may be provided with a forwardly extending duct portion terminating inY an opening adapted to register substantially with a series of louvres in the top of a removable room cover panel through which the heated air is adapted to be discharged into the space to be heated. A second series of louvres at the bottom of the cover -panel may be provided for cool air to enter, and the cover panel is preferably removably mounted on the case. Suitable openings in the cover panel are located to permit access to the thermostat, igniter and other controls of the` heat transfer unit and to permit viewing of the flame during operation. i

Means are also provided for mounting the heating device in a wall structure for use as a wall-inserted circulating space heater. For small units of, for example, 20,000 B. t. u. per hour capacity, the heat transfer means is preferably of dimensions that will permit its installation with necessary accessories between adjacent units of the usual 2 x 4 wall studding which ordinarily is spaced from 13 to 16 inches on centers. For larger units of, for example, `40,000 B. t." u. capacity, a spacing of 26 to 32 inches between alternate studs is generally required. The mounting means as embodied comprises a relatively shallow box-shaped memberhaving an open front and an opening in its back wall dimensioned to permit the passage therethrough of the conduits serving to connect the heat transfer means and the exterior baffle means. The opening is preferably provided with a marginal rearwardly ex-V tending iiange adapted to be lodged in a substantially matching opening formed in the inter-stud wall structure.

Suitable means are provided for securing the box-'shaped member or rough-in box to the exterior wall structure, `for supporting the `con--` vector case in the rough-in box and for supporting the external baflie means from the rough-in box.

Provision is also made for insulating the surrounding wall structure against heat radiated absagen from` the .exhaustl .gas terminal yconduit .and for sealing the wall opening against the elements. Tothis end, the .insulating means, as. embodied, may .comprise an insulating bat for disposition withinztheopening in .the rear wallof the roughi-nlfbox, suitable openingsV being provided in Athe bat for thev passage of the airintahe and exhaust gas .conduits of the heat transfer :means and for the passage. of the Yrequisite bolts or yother means forsecuring the externally disposed Vbaffle' hood' V'means to the rough-in box. The bat is preferably formed of a y-ieldable or resilient heat insulating material, for example, nbre-glass, to allow for variations in wall thickness met in practice and, may be facedA on its' opposite sides withal pair of substantially rigid insulation retaining pa-nels of uniform thickness.` The outer panel of the pair is adapted to be held -rinly'by the external baffle hood member against vthe outer face of vthe rwallstructure and between it and: the external baffle hood means, thereby to provide a removable closure which may be' caulked around -itsr edges `to prevent the entrance off the elements. The inner panel, of substantially identical' size and configuration, is lodged between the rear wall of the con-vector case and the rear wall'of thorough-in box which are suitably spaced from each otherr for' this purpose.

In accordance with this invention also, the rough-in box is dimensioned to provide suicient clearance between its walls and the wallsV of the convector case to permit air to flow constantly during* operation between the two and thereby effect a degree of cooling of the rough-in box which, coupled with the insulating means aboveif:

noted, will ensure adequate protection against undue heating of the wall structure in which the device may be installed.

ft will ybe understood that the foregoing general` description, and the following detailed dei sci-'iption as well, are exemplary and explanatory ofthe invention but are not restrictive thereof;

Referring now more particularly to the accompanying drawings, there is-dep'icted one form of space heating apparatus in accordance with this invention. The device in Figs'. I and 2 in particular is shown installed' in. an outside:v wall structure'l of conventional construction comprising, for example, an inner lath and plaster layer I at the roomV side; verticali studdingf 2' on vthe i usual centers, and an outer sheathing: and' siding lf'ayer at the atmosphere side.` Theheat-i-ng device is' adapted' to be installed in such a wall structure partly'within' and partly' without the spaceto be heated andin its generalorganization comprises a mounting case ror rough-in boxltldiinensioned` for installation' between a pair of the adjacent Vwall studs 2 and having vprovision for attaching it` to the outer sheath-ing layer 3;. aconvector case 5' adapted to' be nested in and carried by the rough-in box: an internally'fired finned heat transfer unit Si adapted 'tof be con--Y tained' in and) carried by the convectorcase; having a. combustion air inlet port 'I and' an exhaust gas outlet port 8; a hood' baille'` 9` adapted to be fixedly-v supported against the outer sheathing layer 3 so as to form an air bypasszchamber at'the' atmospheric side ofthespaceto be'heated, the chamber communicating through thesheath'- ing layer with the ports 'l' andv 8 by adjustable conduitv members its and li, respectively; and, a Alouvred panel-forming member ifadapted to be carried by the convector case as a closure in position over the wall opening and toV form a iinis'l'xing cover for the device at thefrolom. side.

The/heat. transfer .uniti 6 as embodied. is vpreferably .of sectional construction facilitating fabricationr the unit sections preferably .being castings .of aluminum alloy .offering .both light weight. and low cost. and providing more-uniform heat. inv operation. As here preferably embodied, frcnt'and rear sections I4 and .I 5., respectively., are suitably fashionedV to. provide therebetween inassembled:relationship a combustion chamber ILS-*extending generally from-.bottom to top of theunit.

rIvhe combustion chamber 'i6 lis .preferably of greater` `length than width and in such case va ratio of length to width lin the order of two and Aa half to one, has been found to be Vadvantageous. TheV lowerr .end of the combustion chamber forms a burner compartment Il having provision therein for burning a combustible fuel air; mixture' and adapted to be supplied with external fair. for combustion through the air inlet port Except for the air inlet port l and the exhaust gas' port 8,. the combustion chamber I6 is'vr hermetically .sealed so that under operating conditions no communication is provided between the com-bustion chamber and the space to be heated. A substantially uniform taper is prefera'bly/imparted to the combustion chamber from a locus substantially at the top of the burner compartment. i7 to the vtop of thechamber in order to maintain a more uniform velocity of combustion products through the chamber as they cool. To this end, the front and rea-r walls of the unit are disposed inslightly converging relationship from the burner compartment to the top of the unit.

The exhaust gas port 8 is located at some distance. below the top of the combustion chamber and, in vorder to prevent the products of combustion from. flowing` directly out of the exhaust gas port before they havetraversed the entire heatetransfer surface of the. chamber, baiile means are provided .within the chamber i6 substantially at the exhaust port, suchmeans serving to deect the rising stream of combustion products to either side .of the port to the top ofthe combustion chamber before they are permitted to: escape. As here preferably embodied, asubstantially lil-shapedV member i8 integral withthefrontsection i4' of the unit 6, traverses thecombustion chamber substantially from front to rear so as. to provide an open-topped enclosurev extending around .the port 8 from its bottom to above its top. A substantially complementary U.shaped member I9 extends into the com-bustion chamberfor a short distance from the rear section i5 of. the unit 6 with which it is integral and substantially snugly telescopically engages the outer surface of the member I8 at its free end.

A system of heat absorbing fins 2i! in the combustion .chamber I6 provides an extended surface area therewithin for securing a high heat recovery from the hot gaseous products. of combustion moving toward the exhaust port. As here preferably embodied, each of the sections [4i-and: l5 of the heat. transfer unit isA provided with a set ofthe iinsrZ'. integral therewith which project from the one section in` substantial parallelism-(see Figs. 10 and 11) but in staggered relation to the: fins of the other section, for a short distanceinto the combustion'chamber I6. This staggeredl relationship of the. ns of the opposingfsets is best seen in Fig. 6 and'hasthe advantage of! eifecting a high degree ofheat recovery" fromthe combustion products. Each of 9 the flns 20 extends preferably uninterruptedly from the burner compartment I7 through the balance of the length of the combustion chamber I6 except in the vicinity of the deflecting baffle members I8 and I9. In these locations, those fins which would otherwise intersect these members are interrupted a short distance from either side of the ange (see Figs. 10 and 11) so as to avoid blocking of the flow of combustion products by the creation of pocketsat the junc-` tion of the fins and deecting baiile members. Moreover, the fins '20' are preferably omitted entirely within the confines of the baffle memberl9 of the rear section I5 thereby to facilitate the free outward flow in this location of the combustion products through the exhaust port 8. In accordance with this invention also, the fins A2|) are preferably of equal and uniform height throughout their length except over that portion thereof above the baflie members I8 and I9 where a pattern of low and high fins is provided selected to effect a maximum of heat recovery from the hot combustion products in this area under the conditions of fluid flow there existing. To this end, and as is best seen in Fig. 6, the ar-` rangement is such that lfor the respective section I4 and I5, the fin pattern of each section is symmetrical with respect to its vertical median plane S--S in Fig. 6. However, the fins of greater height on one section are disposed opposite the fins of lower height on the other section. In other words the high and low ns on the upper portion of the two body sections I4 and I5 are arranged in staggered relation. By this arrangement' the separate streams of hot gases rising on each side of the baile members I8 and I9 and owing into the portion of the combustion chamber thereabove are caused to pursue a more or less undulating path in turbulent ow toward each other from the opposite sides of the unit, to the common exhaust gas port 8. A high degree of heat recovery in the last stages of the combustion chamber is thereby achieved.

A system of heat-radiating fins 2| is provided on the outer surface of the heat transfer unit 6 operating to provide an extended surface area for Y effecting a high rate of heat transfer to circulating room air flowing upwardly around the unit. As here preferably embodied, the external ns 2| are vertically disposed in separate sets of l parallel or substantially parallel units on and integral with the front and rear sections I4 and respectively (see Figs. 7, 8 and 9). The fins 2| on the front section Iiil extend to the top of the unit 5 from a locus substantially coincident with the top of the burner compartmentl'l whereas the fins on the rear section I5 extend substantially the full length of the unit except at the air inlet and exhaust gas openings l and 8, respectively, vas is best seen in Fig. 9.

`The front section I4 of the heat transfer unit I5 is divided along a line extending from side to side of the unit adjacent the top of the burner compartment I'i, into an upper main body element 22 and a lower cover element 23, the latter constituting a detachable wall portion of the burner compartment and serving as a readily removable closure or cover member therefor, supporting a burner 24 removably in position therewithin; Means are provided for releasably but separately securing the respective elements 22 and 23 to the'rear section I5 in hermetcally sealed relationship to the latter and to each other along their meeting edges. To these ends, the rear section I5 is provided with a continuous 10 marginal groove 25 in which a suitable sealing gasket 26 is adapted to be lodged and compressed throughout the length of the groove by a marginal sealing tongue 21 provided on the upper body element 22 and by a marginal sealing tongue 28 provided on the lower cover element 23. The upper element 22 -is also provided with a bottom marginal groove 29 (Fig. 10) in which a suitable sealing gasket Sil (Fig. 2) is adapted to be lodged and compressed therein by a portion of the tongue 28 formed on burner cover member 23. Bolting lugs 3| formed on and integral with the rear section I5 and with the separate elements 22 and 23 of the front section I4 at suitably spaced intervals function in conjunction with suitable bolting means such as the nut-bolt sets 32, to draw the front and rear sections together into rm sealing engagement with each other at their marginal meeting faces.

The burner means 2li as embodied is detachably carried bythe burner cover 23 so as to be removable ras a unit therewith and is constructed and arranged so as to permit of the burning of a combustible fuel-air mixture within and substantially over the width of the combustion chamber at a level which is preferably slightly above the top of the air-inlet port 1. The embodied burnermeans is of a construction moreover permitting manual adjustment at will of the fuel-air ratio within the burner mixing chamber, from a position outside the heat transfer unit. As here preferably embodied, the burner 24 is provided with a relatively long and narrow flat combustion surface portion having the relatively closely spaced, parallel flame slots 36 which are preferably precisely formed to provide in operation a substantially continuous wall of flame from end to end of the combustion surface portion. The flame slots 36 lead into a header chamber 3'! Iwithin the interior of a header portion 38 of the burner. In order to maintain a substantially uniform distribution of a combustible fuel-air mixture to theame slots 36 over the entire length of the combustion surface 35, theA header portion 38, and hence the header chamber 3l, is provided with a substantially uniform taper from its inlet end (the right hand end as viewed in Fig. 15) to its opposite end and'from bottom to top, as is best seen in Figs. 14 and 16. A hollow Venturi choke portion 39 having communication with the inlet end of the header chamber 31 is disposed directly below the header portion 38 and extends parallel thereto throughout the major portion of its length. The choke portion 39 is integral with the header portion 38 and terminates at its free end a mixing chamber 46 having a fuel supply port 4I and yan air supply port 42. An air valve member 43 is pivotally mounted over the air supply port 44 by means of a screw stud 44 which passes through the valve member 43. into threaded seated engagement with the choke portion 39. The stud 44 when seated should not offer any substantial or material resistance to pivotal movement of the valveV member 43 into and out of position over the air inlet port 42.

Means are provided for detachably, securely supporting the burner 24 within and by the cover member 23 so that the cover-burner assembly may be readily and easily installed in and removed from the heat transfer unit 6, as a unit. The supporting means as here preferably embodied comprisesV a positioning boss 45 integral with the header portion 38, `the boss having a conical recess 46 in its free end providing a seat for a complementary positioning boss 41 integral with the cover member 23. A second positioningbossvl extends outwardly from the burner at the opposite end toward the cover member 23 which in turn is provided'with a complementary boss 49 providing a seat for the boss 48. The bosses 43 and i9 are provided each at their meeting faces with oppositely inclined intersect-ing surfaces since such an arrangement of intersecting surfaces serve to position the burner more accurately with respect to the. cover member, than would be the case where the incl'ned surfaces did not intersect but terminated for example in a plane surface.

A bolting and reinforcing web 56 connects and stiiens the header and choke portions 3S and 39, respectively of the burner and is apertured` as at 5I for the passage of the shank of a securing boltV 52 whose head engages the outer face of the cover member 23. A nut 53 carried by the bolt 52 and bearing against the web 5S serves to draw the burner and burner cover firmly together into the selected position fixed by the locating bosses e5, 4J, 58 andv d5.

Means are provided alsofor adjusting the set-V ting of the air valve shutter d3 from outside the heat transfer unit 5, for controlling the fuel-air ratio of the combustible mixture at the burner mix-ing chamber. As here preferably embodied, the shutter d3 is provided with an adjusting lever arm i55 which is integral with themain body portion of the shutter but disposed in overlying spaced. relation to the shutter pivot pin 4.4i. The arm 55 is. apertured as at 55 to receive, in nonrotatable engagement therewith, the terminal portionof a screw El' whose shank is coaxially aligned with the pivot pin lid and passes through the. Vcover member` 23 in threaded engagement therewith A lock nut 58 on the screw shank at the outside of the cover member permits of xing Ythescrew, and hence the shutter member d3, in a determined selected position to which the screw may be turned by means of a suitable tool (not shown) engageable with the screw head.

Means are provided within the combustion chamber 11S for minimizing localized heating of the heat transfer unit in the wall areas thereof closely adjacent to the ame created by the burner 2li when in operation. The embodied means functions to establish. a generally .annular insulating layer of relatively `fast moving and cool air within the combustion `chamber circum.- ferentially of the .combustion surface 35 of the burner between the intensely hot burner flame and the contiguous wall portions of the heat tansfer. unit front and rear sections ld and l5 of.' the heat transfer unit are provided within the combustionY chamber i5 each with a substantially horizontal.

surface portion 5G (Fig. 2) extending toward the other' for a short distance `so as to form an air guiding baiiie extending continuously circumferentially of the combustion surface 35 of the burner. Thus, secondary air for combustion entering the burner compartment l'i through the air inlet port 'i will flow upwardly around the burner and through the more vor less annular restricted passage between. it and the air guiding baie d.

In.accordance with this invention also, the heat transfer unit E. is provided with suitable thermostatically controlled safety pilot means preferably removableas a unit with the burner-cover assem bly. The burner cover 23 is provided in its bottom surface for this purpose with an. aperture Si (Fig. 14') through which .a safety-pilotunit ex.-

As here preferably embodied the.

Gil

tends upwardly into the. burner compartment in operative relationship to the burnerv 24 therewithin. Units of this .nature are well-known in the gasheating industry and the details thereof are unimportant. In general, however, the unit comprisesthe pilot burner Y62 (Fig. 13) disposed alongside a valved thermo-responsive main fuel supply header e3 having a conventional spud connection lili-with the fuel supply porti-l (Fig. 15) of the burner 24, as indicated in Fig. 3. Both the fuel supply headerl .53 and the pilotV burner E2 are carried by ar flanged header fitting 65 (Fig. l2f) sealingly engaging the covermember 23 about the aperture 6.-! and having connection with a main fuel supply pipe @56; and with a by--pass pipe `5'! (Fig. 2) for supplying fuel to the pilot burner. rThe main fuel supply pipe 66 is provided with a' manually adjustable thermostatically controlled fuel supply valve S8- to4 which access .may be had for setting through an aperture "59 in the room panel-member I3.

Suitable igniter means are also provided enabling the pilot burner 62 to. be ignited without opening thev .heat transfer'unit.. As here preferably embodied, anligniter plug` i8. is screwed into the face'of `the burner cover 23 (see Fig. 13) anclis providedwith an igniter wheel ll journal-led by means ofa shaft L2 in the plug and adaptedv to frictionally engage .a spring-pressedflint T3 for producing a stream of sparksdirected against the pilot burner 62. The shaft lf2 ter mina-tes in a manually engageable end portion and the plug ispreferably sealed `against leakagevof combustion products around the shaft if.'

-V by mea-ns of a sealing cap 13a whichtthreadedly removably engages `the plug and extends through an opening 1li in the room panel cover I3. It. will be under-stood thatrthe burner cover 23fmay be provided additionally with a. separate plugged lighter opening (notshown) preferablyadjacent thev pilot burner 52, through whichv the pilot burner may be lighted with amatch, if safety requirementsnecessitate such a construction. An observation port 'F5 (Fig. .1.0) in the front section iii-of the heat transfer unit is suitably located w-ith reference to the combustion surface 3501 the burner 2li as to permit viewing the flame through a companion observation port 'i6 in the room panel, as indicated by the dot dash sight linesy in Fig. 2. The port .75 .may comprise a quartz window suitably detachably mounted inY the section lll. The external ns 2l are preferably terminated slightly above theport i5 (Fig. d) in the areaimmediately surrounding the port so as to minimize obstruction of thesight line.

The heat transfer unit E is supported from the convector case 5 by means of a set of rearwardly extending brackets 1.?, whichY as Ahere preferably embodied are. four in. number. and are cast integral with the rear section i5 of the unit. The brackets are releasably secured to the convector case each by a nut-bolt unit 163 or other suitable securing means.

Fixed conduits T8 and 'i9 cast integral with the rear section l5 of the heat transfer unit extend rearwardly therefrom in parallel relation to each other, from the air inlet and exhaust gas ports 'I and 8, respectively. The free terminus of these conduitslies in substantially the same plane and they are preferably of rectangular contour with their long axis vertically disposed.

The adjustable conduits IQ and H previously.

mentioned are of complementary contour in cross-section to the fixed conduits T8 and T9, respectively, andv are snugly but freely, slidably 1=9 respectively, and are of a length taken each with that of its companion xed conduit, as to provide therewith a duct axially variable in length an amount suflicient to permit the duct to extend or be extended through a suitable opening in Walls of substantially different thicknesses, to the atmosphere side of the space to be heated.

The adjustable conduits i I8 and Il terminate at their outer ends in the hollow interior ofthe hood baie 9 which bafe provides an air bypass chamber 8| between the conduits at the atmosphere side thereof and provides also a system of air-directing and guiding vanes and surfaces for funneling combustion air into `the burner compartment I1 through the air inlet duct formed through the k'exhaust gas duct formed by thev conduits II and 19, thereby ensuring the maintenance of a yunidirectional flow of air for combustion and of products of combustion, through the combustion chamber regardless of the d irection or velocity of the wind at the atmosphere side of the hood bale.

` The hood baffle 9 is secured in position over the outer ends of the conduits I and I I by suitable means such as the pair of stay bolts 82 releasably anchored at their inner ends each to a separate unit of a pair of anchor brackets 83 xedlysecured to the rough-in box 4 (Figs. 2 and 5)', preferablyin parallelrelation to each other, across an elongated opening 84 in the rear wall of the rough-in box.

A stift` panel 85 of suitable heat insulating and weather-resistant material isv provided for disposition between the vhood-baite 9 and the outer sheathing` layer of the building structure. The panel member 85 is suitably apertured for the passage of the conduits I8V and II and of the hood-baiile anchor bolts 82, but is otherwise preferably imperforate. Itv functions to seal the opening formed Yin the wall structure against the elements, to which end it may be caulked around its edges, and it also provides a closure for the opening 84 in the rough-in box and for the hood-bailie.

The hood-baille 9 as here preferably embodied is a relatively elongated and more or less panshaped or trough-like member adapted to be installed in an upright position with its long axis substantially vertical and with its interior presented `to the conduits II) and II. Thus disposed, the hood-baflle 9 offers to the atmosphere asubstantially flat-surfaced outer wall 88 substantially paralleling the sheathing `layer 3 in closely spaced relation thereto, and top, bottom and side walls which fall substantially directly away from the wall 86 to the panel member 85 with which they make substantially sealing engagement.

An air-inlet opening 81 (Fig. 4) is provided in the wall 86 opposite theV mouth of the conduit I0 and a system of air-directing and guiding surfaces and vanes is provided at the opening 81 for funneling moving air therethrough into the conduit I8 regardless of the direction from which the moving air stream approaches the hood-baffle in the immediate vicinity of the opening 81.

The vane system ashere preferably embodied, comprises vertical and horizontal vanes 88 and 89, respectively. intersecting each other and extending from the wall 88 at right angles or substantially right angles thereto. The vertical vane 88 bisects the opening 81 into equal parts and preferably extends for a short distance above its top margin While terminating substantially at its bottom margin. The horizontal vane 89 also bisects the opening 81 but is preferably located nearer the bottom margin of the opening 81 than its top margin, and advantageously at about two-thirds of the distance down from the top margin. Moreover, the horizontal vane 89 is preferably of somewhat greater width than that of the opening 81 and extends a greater distance out from the wall 86 than does the vertical fin 88. A gradual reduction in width of the vane 89 to that of the opening is effected however at a short distance from the opening and the vane is preferably extended through the opening into the chamber 8I for a substantial distance thereacross, advantageously for twothirds of the distance across the chamber toward the mouth of the conduit I8.

In addition to the vanes 88 and 89. side vanes 98 are provided one on each side of the opening. The vanes 98 extend from substantially the bottom margin to alevel somewhat above the top margin of the opening and are disposed at angles to the wall portion 86 in outwardlydiverg-4 ing relation thereto, advantageously at an angle` of about 45 to the wall 88 so as to form a funnel entrance to the opening.

It will be noted that from the arrangement and disposition of the vanes 88, 89 and 90 at the mouth of the air-inlet opening 81, air moving either across or at angle to the plane of the opening will be intercepted and directed, that is, funnelled into' the opening 81 into the conduit. Moreover, strong down drafts or up drafts are intercepted by the correspondingly large area horizontal vane 89 and diverted into the opening 81 with eoual facility. Strong upward movement of air in the air bypass cham# ber 8l which would tend to blanket the exhaust gas duct opening at the top of the air bypass chamber, is substantially eliminated by the ex'i4 tension of the horizontal vane 89-into the chamber 8|. Thus, an air stream moving rapidly upward against the horizontal vane 89 would be deflected into the opening, but would be prevented from coursing'upwardly in the pressureequalizing chamber 8I by the portion of the vane 89 in the chamber. The low position of the inner extensionof the vane 89 is of particular importance where the upwardly moving Vair stream is at a small angle of approach to the plane of the opening 81. While the vane 89 tends to prevent strong upward coursing of air through the chamber 8l when the wind striking the vane has an upwardly directed component, the construction Vis such that under wind conditions the pressure within the lower end of the chamber 8| is always slightly greater than the pressure at the upper end of this chamber, thus assuring unidirectional flow of the air and products of combustion past the burner and through the combustion chamber and heat exchanger. Under most conditions, this pressure difference between the lower end and the upper end of the chamber 8l is very minute, but it will, under all wind conditions, be suicient to cause some relatively slow bypassing of air upwardly through the chamber and thus preclude any possibility of reverse flow whereby the products of combustion from the outlet II might flow downwardly through the chamber BI and into the` inlet I8. Such recirculation of the products` of combustion` through the combustion chamber might 'face of the heat ytransfer unit 6 where it is adapted to discharge heated air into the space to be heated thro-ugh a series of louvred openings formed in the room panel or cover I3.

The openings |05 are sufficient in number and area to permit of the discharge of heated air therethrough in the quantities issuing from the convector oase discharge duct IM and to permit heated air which rises upwardly between the convector case and rough-in box into the space above the air discharge duct i041, to escape into the spaceto be heated through the openings H35.

'Louvred openings H31 for the entry of the air to be heated are provided in the bottom portion of the panel cover I3 opposite the lower end of the convector case 5. Thus, cool air flows through these openings both into the interior of the convector case atthe bottom and into the space around the convector case between the case and the rough-in box. In flowing upwardly over the .heat transfer unit 6 the air is heated rapidly in` a short distance as a result of the high heat generating and heat radiating capacity of the heat transfer unit, and is discharged through the duct portion I via the openings Iii back into the room. At no time, however, will there be any commingling of the room air with the products of combustion formed in the hermetically sealed combustion chamber I6 of the heat transfer unit 6.

Mounting of the room panel I 3 in position over the opening formed in the wall structure to accommodate the elements of the heating apparatus as a whole is eifected by means of a series of brackets |08 carried by the convector case 5 and extending forwardly therefrom in opposition to the panel cover I3 to a locus where they are engaged by screws |09 passing through the panel cover into threaded engagement with the free ends of the brackets |08. The panel cover is of a configuration serving to enclose completely the opening in the wall structure and by reasonof the compactness of the unit as a whole enabling its installation between adjacent wall studs, thepanel cover extends but a short distance into the space to be heated.

VIt will be apparent that access to the heat transfer unit 6 may be readily effected by re- :moval of the panel cover I 3. Likewise, access `to the burner for any purpose is readily effected by simply removing the burner cover 23 andv .the burner with it in a single operation.

, The invention in its broader aspects is not limited to the specific vmechanisms shown and ydescribed but departures may bemade therefrom, 'within the scope of the accompanying claims, lwithout departing from the principles of the invention and without sacrificing its chief advantages.

.What is claimed is:

1. A heating device comprising in combination a finned hollow heat transfer member having in Ione wall a combustion air inlet opening and an exhaust gas opening in close proximity to each other; a burner for iiuid fuel in the interior of said member adjacent said air inlet opening; air deecting vanes in the interior of said member at opposite sides of said burner; valve means on said burner` for controlling the primary air intake thereof; means operable from outside said member for adjusting said valve means; external baiille means .including a pluralityof air directing vanes and surfaces for maintaining a unidirectional flow of combustion air and combustion products ih lllh .Sad member .item .Seid air 18 inlet'opening to said exhaust lgas opening, said baffle means providing a connecting chamber between said openings; and conduit means for connecting said chamber to the interior of said heat transfer member at said openings.

2. A heating device comprising in combination a hollow heat transfer member providing a combustion chamber having spaced front and rear walls, a combustion air inlet opening in said rear wall adjacent one end of said member, a removable wall portion in said front wall opposite said opening, an exhaust gas opening in said rear wall between the other end of said member and said air inlet opening, and stream dividing baie means extending between said walls at said exhaust gas opening; burner means, burner pilot means and burner air valve adjusting means car ried by said removable wall portion for removal therewith; and, external baffle means including a hood baffle member providing a connecting chamber between said openings andconduits for maintaining a unidirectional liow of combustion air through said heat transfer member from said air inlet opening to said exhaust gas opening.

3. A space heating device comprising in combination a rough-in box adapted for installation between adjacent wall studs on the inside of a building structure; a convector case lodged in said rough-in box in spaced relation thereto; a hollow finned heat transfer member forming a hermeticalljr sealed combustion chamber disposed in said convector case in spaced relation thereto; a baille member adapted for installation at the outside of the building structure so as to provide an air bypass chamber, said member having an air inlet opening and an exhaust gas opening in substantially the same static pressure area; conduit means for connecting said openings and said air bypass chamber with said combustion chamber through said wall structure; and, a room panel cover for said convector case having an opening for admitting air to be heated to said convector case and a separate opening for the discharge of heated air therefrom.

4. A space heating device comprising in combination a hollow heating member for disposition in a compartment containing a fiuid medium to be heated, said member forming a combustion chamber hermetically sealed except for an air inlet opening in one wall of said chamber and a separate exhaust gas opening in the same wall, said member having both internal and external iins providing extended heat transfer surfaces, having a flow-reversing baille in said combustion chamber 'between said air inlet and exhause gas openings, and having means for burning a com bustible iiuid'mixture in proximity to said air inlet opening; an elongated hollow baflie member forv disposition outside of said compartment with its long axis vertical for effecting a unidirectional flow of combustion air and combustion products through said heating member from said air inlet opening to said exhaust gas opening, said member having an air inlet opening at its lower end and a separate but communicating exhaust gas opening at its upper end having a horizontally disposed air deflecting vane extending through its said air inlet opening into its interior and dividing its said air inlet opening into unequal areas, having a vertically disposed deiiecting vane bisecting its said inlet opening, having a pair of vertically disposed -deflecting vanes at opposite sides of its said inlet opening and vat an angle to said vertical vane, and having deflecting vanes interiorly at its top forming a Venturi passageway at its said 19 exhaust gas opening; and, a pair of conduits for connecting the interior of said baiiie member to the opening in said heating member,

5. In a heater adapted to heat an enclosed space and having a sealed heat transfer member including a burner compartment and a heat exchanger, the combination comprising means forming a pair of ducts connected at one end to said member and adapted to communicate at the other end with the atmosphere exterior to the space to be heated to provide respectively an inlet for combustion air and an outlet for products of combustion at points relatively closely spaced vertically so as to be in substantially the same static pressure region, a windguard including an elongated hollow box-like member extending over both said inlet and outlet and having openings in its walls respectively for admitting air to the inlet and for the escape of exhaust gases from said outlet to the atmosphere, bafe structure at the inlet opening to said windguard to break up cross currents of atmospheric air and direct the same into said inlet in an endwise direction, and means including oppositely disposed openings in said box-like member and other baffle structure at the outlet for exhaust gases from said windguard of Venturi formation to create a pressure drop at said outlet in the presence of cross currents of atmospheric air.

6. In a heater adapted to heat an enclosed space and having a sealed heat transfer structure including a burner compartment and a heat exchanger, the combination comprising means forming a pair of ducts connected at one end to said member and adapted to communicate at the other end with the atmosphere exterior to the space to be heated at relatively closely spaced points of substantially the same static pressure to provide an inlet for combustion air and an outlet for products of combustion, a windguard including an elongated box-like member forming a cover extending over both said inlet and outlet and having a wall spaced outwardly therefrom with openings in the portion thereof opposite said inlet and oppositely disposed openings in other wall portions located adjacent said outlet in planes substantially normal to the transverse plane of the outlet, a baifle structure at the opening opposite said inlet including parts providing surfaces to break up currents of outside air at said opening and direct the air into said inlet in a substantially7 endwise direction, and a Venturilike structure in the path of flow of currents of outside air adjacent said outlet opening to cause a slight suction at said outlet in the presence of such currents.

7. In a heater adapted to supply heat within an enclosed space and having a sealed heat transfer member including a burner compartment and a heat exchanger, the combination comprising means forming a pair of ducts connected at one end to said member and adapted to communicate at the other end with the atmosphere exterior to the space to be lsupplied with heat at relatively closely spaced points to provide an inlet for combustion air and an outlet for products of combustion, a windguard including an elongated hollow box-like member extending over both said inlet and outlet and having a wall spaced outwardly therefrom with openings in one portion thereof opposite said inlet and oppositely disposed openings in other wall portions located adjacent said outlet in planes substantially normal to the transverse plane of the outlet, a baie structure at the opening opposite said inlet including portions extending inwardly and outwardly of thev plane of said opening to break up currents of outside air at the said opening and direct the said air into said inlet in a substantially endwise direction, and baiiles adjacent said outlet cooperating with the wall structure of the hood defining said openings to cause slight suction at said outlet when currents of outside air iiow through said openings.

8. In a heater for supplying heat to an enclosed space having a sealed heat transfer member including a burner compartment and a heat exchanger, the combination comprising means forming a pair of ducts connected at one end to said member and adapted to communicate at the other end with the atmosphere exterior to the space to be heated at relatively closely vertically spaced points of substantially the same static pressure to provide an inlet for combustion air and an outlet for products of combustion, a windguard including an elongated box-like member forming a cover extending over both said inlet and outlet and having a wall spaced outwardly therefrom with an opening in the portion thereof opposite said inlet and oppositely disposed openings in other wall portions located adjacent said outlet in planes substantially normal to the transverse plane of the outlet, a vertically disposed baffie structure extending outside of the opening adjacent said inlet a substantial distance, and a horizontally disposed baille below the center of the said opening extending from the inside of said opening to the outside thereof a distance at least equal to the distance said vertical bafe structure extends outwardly of the opening, and a baliie on that vertical edge of each of the openings adjacent the outlet, said baliles being inclined inwardly so as to create a Venturi effect at said outlet should cross currents of outdoor air be blown through said opening.

9. In a heater of the class described, a hollow relatively thin member of rectangular outline including matching front and back wall structure defining a burner chamber in the lower end thereof and a combustion chamber and heat exchanger in the upper end thereof communicating with said burner chamber, said burner chamber having an inlet for combustion air and said combustion chamber having an outlet for products of combustion intermediate its upper and lower ends, a plurality of heat absorbing ns on the internal walls of said combustion chamber, and baille structure extending fromfront to back of said combustion chamber around the lower edge of said outlet and the opposite sides thereof to points disposed upwardly of the top edge of the outlet and laterally outwardly of the opposite ends of said top edge to direct products of combustion from said burner upwardly and outwardly relative to the outlet in the course of their ow from the burner to the outlet, said iins above said outlet being of vari-ableV height with the ns of greater height on one wall staggered with respect to the fins of lower height on the opposite wall to produce a tortuous flow of products of combustion in the upper end of said heat exchanger toward said outlet.

l0. In a heater which includes a hollow structure forming a combined combustion chamber and heat exchanger with an elongated opening along its bottom side and a portion depending below one of the elongated sides of said opening, the combination comprising elongated wall structure removably secured to said depending portion and cooperating therewith to form a sealed burner compartment communicating with said 21 combustion chamber through the said opening in its bottom side, a gaseous fuel burner of substanti-ally the same length as the opening in the bottom side of said combustion chamber removable with said removable wall and supported at the said opening when said removable wall is in position, means carried by said removable wall and connected to said burner to supply va combustible mixture to the latter, means carried by said removable wall to ignite the fuel at said burner, means for admitting air for combustion to said burner compartment including an opening in its wall opposite said removable wall,

a valve in said burner compartment to control the ilow of primary air to said burner, and means extending through said removable wall for manipulating said valve from the exterior.

11. In a heater which has a sealed hollow heat transfer member including a combustion chamber and an elongated burner compartment communicating therewith through an opening in the bottom of said combustion chamber, the combination comprising a removable wall structure forming one of the sides of said burner compartment, an elongated burner assembly in the burner compartment connected to the removable wall and removable therewith from the burner compartment, fuel supply means carried by said removable wall and connected to said burner to supply a combustible mixture thereto, means for admitting air for combustion to said burner compartment, a valve in said burner compartment to control the ilow of primary air to said burner including a member extending to the exterior of said compartment for manually -adjusting said valve from the exterior, and means to ignite the fuel at said burner including a pilot light in said burner compartment and a friction type igniter for the pilot light both removable with the removable wall, said igniter having a part extending to the exterior for manual manipulation.

12. In a heater which has a sealed hollow heat transfer member including a combustion chamber and an elongated burner compartment communicating therewith through an opening in the bottom of said combustion chamber, the combination comprising a removable wall structure forming one of the sides of said burner compartment, an elongated burner assembly in the burner compartment connected -to the removable wall and removable therewith from the burner compartment, fuel supply means connected to said burner and said removable wall including a part exterior to said burner compartment, a valve in the portion of said fuel supply means exterior to said burner compartment for regulating the supply of fuel to the burner, means for admitting air for combustion to said burner compartment, a valve on said burner to control the flow of primary air thereto including a part extending through said removable wall for manipulating said valve from the exterior. of said burner compartment, and means carried by said removable wall in said burner compartment for igniting the burner including a part extending through the said wall to the exterior of said compartment for manual manipulation.

13. In a heater which has a hollow generally rectangular heat transfer member including a combustion chamber and an elongated burner compartment communicating therewith through anelongated opening in the bottom of said combustion chamber, the combination comprising a removable wall secured to said member over said elongated opening, a gaseous fuel burner extending lengthwise of said burner compartment substantially at the level of the opening in said combustion chamber and secured to the removable wall, means to supply a combustible mixture to said burner, means for igniting the fuel mixture at said burner including a pilot light in said burner compartment adjacent one end of said burner, means for admitting air for combustion to said burner compartment including an opening in its wall opposite said removable wall, and a baille structure removable with the removable Wall and adjacent said pilot light on the side thereof between the combustion air inlet opening to said burner compartment and said pilot light to prevent direct impingement of drafts of air from said combustion air inlet onto said pilot light.

14. In a heater of the type adapted to be disposed in a recess in a portion of the wall defining the space to be heated, a heat transfer member providing heat `exchange surfaces on opposite sides thereof, separate duct-forming means connected to said heat transfer memberto provide an inletI for combustion air and an outlet for products of combustion, a generally box-like de- 'iiector of larger overall dimensions than said heat transfer member, means to support the latter in said deflector in spaced relation thereto to form'passageways for Ventilating air around said heat transfer member, a second box-like member of smaller overall dimensions than the said recess adapted to be anchored to the said wall portion in spaced relation to the sides of said recess, means iixedly to anchor said deflector in spaced relation to said box-like member, said deiiector having apertures to pass said inlet and outlet ducts, an apertured interior cover panel member of larger overall dimensions than said recess adapted to be anchored to said heater in sealed relation with the said wall portion for concealing said recess and the heater structure, said box-like member having a flanged opening in its rear wall adapted to project outwardly through an opening in the wall portion in which said recess is formed when said box-like member is anchored in position, and a closure for said opening in said box-like member through which said inlet and outlet ducts pass to the exterior including material of low thermal conductivity for thermally insulating said ducts from said wall portion.

15. In a heater located in an enclosed space and comprising a sealed combined burner and heat exchanger housing, said housing having an inlet conduit at its bottom and an outlet conduit near its top, inlet and outlet extensions telescopically fitting said inlet and outlet conduits respectively for adjustment of the eifective lengths thereof, said conduits and extensions being adapted to extend through the wall of the room in which the heater is located to the outside atmosphere in close proximity in substantially the same static pressure area, and a baffle structure adapted to be located on the outside of the wall and partially covering the end openings of both of said conduit extensions, said baiile structure providing means for causing unidirectional flow of air into the heater and the products of combustion therefrom under all wind conditions and having means for the conduction of heat derived from the exhaust gases to the portion of baffle structure adjacent the inlet extension opening.

16. In a heater located in an enclosed space and comprising a sealed combined burner and heat exchanger housing, said housing having an 23' inlet conduit at .its bottom and .-an outlet conduit near its top, inlet and voutlet extensions telescopically iitting said inlet and outlet conduits respectively .for adjustment of .the effective lengths thereof, said conduits and extensions being adapted to extend to the outside atmosphere through an opening in the wall of the room in Which the .heater is located, a relatively stiff heat insulating sheet adapted to be placed on the outside of the wall and covering the opening therein, a sheet forming part of the heater structure for closing said wall opening inside the Wall, said sheets having apertures for the conduit extensions, a bat of compressible insulating `material surrounding the outlet conduit extension between said sheets and filling the space therebetween, means adapted to clamp said 4sheets against the portion of the wall surrounding the opening, and a bale structure adapted to be located on the outside of the wall and partially covering the end openings of both of said conduit extensions, said baiile structure providing means for causing unidirectional flow of air into the heater and the products of combustion therefrom under all wind conditions.

17. A space heating device comprising in combination a rough-in box adapted for installation between adjacent wall studs on the inside of a building structure, a convector case lodged in said rough-in box in spaced relation thereto; a hollow heat transfer member forming a hermetically sealed combustion chamber' disposed in said convector case in spaced relation thereto; a baiile structure adapted to be located outside of the building structure, secured to the rough-in box, .and providing an air bypass chamber, said Cil 24 baliie structure .having spaced air inlet and exhaust gas openings located in lsubstantially the same static pressure area; inlet and outlet conduits krespectively connecting the combustion chamber to said baille structure adjacent the air inlet and exhaust gas .openings thereof, said conduits adapted to .extend through the wall of the building structure, and a room panel cover `for said convector case having openings Vfor the admissionand discharge of air to be heated by the heat transfer member and forming the front wall portion of the convector case.

ALLAN W. LUNDS'IRUM.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED ySTATES PATENTS 'Number Name Date 1,574,145 Andrews Feb. 23, 1926 1,582,657 Andrews Apr. 27, 1926 1,695,079 Barnhart Dee. 11, 1928 1,790,777 Torr Feb. 3, 1931 1,814,076 4Carnahan July 14, 1931 2,087,983 Martin July 27, 1937 2,158,643 Wacek May 16, 1939 2,160,264 Furlong May 30, 1939 2,160,883 Luhdstium June 6, 1939 2,192,920 Linch `Mar. 12, 1940 2,292,180 Tuck Aug. 4, 1942 2,422,694 McCollum June 24, 1947 FOREIGN PATENTS Number Country Date 646 Great Britain of 1872 

